Media devices are in common use among a broad base of users. Radio and television have provided entertainment for generations of users. Portable transistor radios of the 1960s began a trend to smaller and more robust personal media devices including very small devices storing all digital content on both rotating and non-rotating media. Streaming media is available over both wireless and wired networks and may be displayed on cellular telephones and other portable media devices.
File transfer among devices of all kinds is known and understood. Different protocols, such as file transfer protocol (FTP), establish the protocol for sending a file between two systems. Other protocols, such as extended markup language (XML) or ISO 7816 application protocol data units (APDU) allow for name/value pairs of data that allow a definition of the data to be sent with data. However, protocols such as ISO 7816 require hexadecimal tags that require machine interpretation. Similarly, XML often requires a separate XML schema definition (XSD) file to be sent separately from an associated XML file. While data contents are defined by these protocols, relationships between files or other data elements are not defined by existing file transfer protocols, requiring a priori information about data relationships.